975db80ef6
Pointers can be either uniform or varying, and behave correspondingly. e.g.: "uniform float * varying" is a varying pointer to uniform float data in memory, and "float * uniform" is a uniform pointer to varying data in memory. Like other types, pointers are varying by default. Pointer-based expressions, & and *, sizeof, ->, pointer arithmetic, and the array/pointer duality all bahave as in C. Array arguments to functions are converted to pointers, also like C. There is a built-in NULL for a null pointer value; conversion from compile-time constant 0 values to NULL still needs to be implemented. Other changes: - Syntax for references has been updated to be C++ style; a useful warning is now issued if the "reference" keyword is used. - It is now illegal to pass a varying lvalue as a reference parameter to a function; references are essentially uniform pointers. This case had previously been handled via special case call by value return code. That path has been removed, now that varying pointers are available to handle this use case (and much more). - Some stdlib routines have been updated to take pointers as arguments where appropriate (e.g. prefetch and the atomics). A number of others still need attention. - All of the examples have been updated - Many new tests TODO: documentation
334 lines
10 KiB
C++
334 lines
10 KiB
C++
// -*- mode: c++ -*-
|
|
/*
|
|
Copyright (c) 2010-2011, Intel Corporation
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
* Neither the name of Intel Corporation nor the names of its
|
|
contributors may be used to endorse or promote products derived from
|
|
this software without specific prior written permission.
|
|
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
|
|
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
|
|
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
|
|
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
/*
|
|
Based on Syoyo Fujita's aobench: http://code.google.com/p/aobench
|
|
*/
|
|
|
|
#define NAO_SAMPLES 8
|
|
#define M_PI 3.1415926535f
|
|
|
|
typedef float<3> vec;
|
|
|
|
struct Isect {
|
|
float t;
|
|
vec p;
|
|
vec n;
|
|
int hit;
|
|
};
|
|
|
|
struct Sphere {
|
|
vec center;
|
|
float radius;
|
|
|
|
};
|
|
|
|
struct Plane {
|
|
vec p;
|
|
vec n;
|
|
};
|
|
|
|
struct Ray {
|
|
vec org;
|
|
vec dir;
|
|
};
|
|
|
|
static inline float dot(vec a, vec b) {
|
|
return a.x * b.x + a.y * b.y + a.z * b.z;
|
|
}
|
|
|
|
static inline vec vcross(vec v0, vec v1) {
|
|
vec ret;
|
|
ret.x = v0.y * v1.z - v0.z * v1.y;
|
|
ret.y = v0.z * v1.x - v0.x * v1.z;
|
|
ret.z = v0.x * v1.y - v0.y * v1.x;
|
|
return ret;
|
|
}
|
|
|
|
static inline void vnormalize(vec &v) {
|
|
float len2 = dot(v, v);
|
|
float invlen = rsqrt(len2);
|
|
v *= invlen;
|
|
}
|
|
|
|
|
|
static inline void
|
|
ray_plane_intersect(Isect &isect, Ray &ray, Plane &plane) {
|
|
float d = -dot(plane.p, plane.n);
|
|
float v = dot(ray.dir, plane.n);
|
|
|
|
cif (abs(v) < 1.0e-17)
|
|
return;
|
|
else {
|
|
float t = -(dot(ray.org, plane.n) + d) / v;
|
|
|
|
cif ((t > 0.0) && (t < isect.t)) {
|
|
isect.t = t;
|
|
isect.hit = 1;
|
|
isect.p = ray.org + ray.dir * t;
|
|
isect.n = plane.n;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static inline void
|
|
ray_sphere_intersect(Isect &isect, Ray &ray, Sphere &sphere) {
|
|
vec rs = ray.org - sphere.center;
|
|
|
|
float B = dot(rs, ray.dir);
|
|
float C = dot(rs, rs) - sphere.radius * sphere.radius;
|
|
float D = B * B - C;
|
|
|
|
cif (D > 0.) {
|
|
float t = -B - sqrt(D);
|
|
|
|
cif ((t > 0.0) && (t < isect.t)) {
|
|
isect.t = t;
|
|
isect.hit = 1;
|
|
isect.p = ray.org + t * ray.dir;
|
|
isect.n = isect.p - sphere.center;
|
|
vnormalize(isect.n);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static inline void
|
|
orthoBasis(vec basis[3], vec n) {
|
|
basis[2] = n;
|
|
basis[1].x = 0.0; basis[1].y = 0.0; basis[1].z = 0.0;
|
|
|
|
if ((n.x < 0.6) && (n.x > -0.6)) {
|
|
basis[1].x = 1.0;
|
|
} else if ((n.y < 0.6) && (n.y > -0.6)) {
|
|
basis[1].y = 1.0;
|
|
} else if ((n.z < 0.6) && (n.z > -0.6)) {
|
|
basis[1].z = 1.0;
|
|
} else {
|
|
basis[1].x = 1.0;
|
|
}
|
|
|
|
basis[0] = vcross(basis[1], basis[2]);
|
|
vnormalize(basis[0]);
|
|
|
|
basis[1] = vcross(basis[2], basis[0]);
|
|
vnormalize(basis[1]);
|
|
}
|
|
|
|
|
|
static inline float
|
|
ambient_occlusion(Isect &isect, Plane &plane, Sphere spheres[3],
|
|
RNGState &rngstate) {
|
|
float eps = 0.0001f;
|
|
vec p, n;
|
|
vec basis[3];
|
|
float occlusion = 0.0;
|
|
|
|
p = isect.p + eps * isect.n;
|
|
|
|
orthoBasis(basis, isect.n);
|
|
|
|
static const uniform int ntheta = NAO_SAMPLES;
|
|
static const uniform int nphi = NAO_SAMPLES;
|
|
for (uniform int j = 0; j < ntheta; j++) {
|
|
for (uniform int i = 0; i < nphi; i++) {
|
|
Ray ray;
|
|
Isect occIsect;
|
|
|
|
float theta = sqrt(frandom(&rngstate));
|
|
float phi = 2.0f * M_PI * frandom(&rngstate);
|
|
float x = cos(phi) * theta;
|
|
float y = sin(phi) * theta;
|
|
float z = sqrt(1.0 - theta * theta);
|
|
|
|
// local . global
|
|
float rx = x * basis[0].x + y * basis[1].x + z * basis[2].x;
|
|
float ry = x * basis[0].y + y * basis[1].y + z * basis[2].y;
|
|
float rz = x * basis[0].z + y * basis[1].z + z * basis[2].z;
|
|
|
|
ray.org = p;
|
|
ray.dir.x = rx;
|
|
ray.dir.y = ry;
|
|
ray.dir.z = rz;
|
|
|
|
occIsect.t = 1.0e+17;
|
|
occIsect.hit = 0;
|
|
|
|
for (uniform int snum = 0; snum < 3; ++snum)
|
|
ray_sphere_intersect(occIsect, ray, spheres[snum]);
|
|
ray_plane_intersect (occIsect, ray, plane);
|
|
|
|
if (occIsect.hit) occlusion += 1.0;
|
|
}
|
|
}
|
|
|
|
occlusion = (ntheta * nphi - occlusion) / (float)(ntheta * nphi);
|
|
return occlusion;
|
|
}
|
|
|
|
|
|
/* Compute the image for the scanlines from [y0,y1), for an overall image
|
|
of width w and height h.
|
|
*/
|
|
static void ao_scanlines(uniform int y0, uniform int y1, uniform int w,
|
|
uniform int h, uniform int nsubsamples,
|
|
uniform float image[]) {
|
|
static Plane plane = { { 0.0f, -0.5f, 0.0f }, { 0.f, 1.f, 0.f } };
|
|
static Sphere spheres[3] = {
|
|
{ { -2.0f, 0.0f, -3.5f }, 0.5f },
|
|
{ { -0.5f, 0.0f, -3.0f }, 0.5f },
|
|
{ { 1.0f, 0.0f, -2.2f }, 0.5f } };
|
|
RNGState rngstate;
|
|
|
|
seed_rng(&rngstate, y0);
|
|
|
|
// Compute the mapping between the 'programCount'-wide program
|
|
// instances running in parallel and samples in the image.
|
|
//
|
|
// For now, we'll always take four samples per pixel, so start by
|
|
// initializing du and dv with offsets into subpixel samples. We'll
|
|
// take care of further updating du and dv for the case where we're
|
|
// doing more than 4 program instances in parallel shortly.
|
|
uniform float uSteps[4] = { 0, 1, 0, 1 };
|
|
uniform float vSteps[4] = { 0, 0, 1, 1 };
|
|
float du = uSteps[programIndex % 4] / nsubsamples;
|
|
float dv = vSteps[programIndex % 4] / nsubsamples;
|
|
|
|
// Now handle the case where we are able to do more than one pixel's
|
|
// worth of work at once. nx records the number of pixels in the x
|
|
// direction we do per iteration and ny the number in y.
|
|
uniform int nx = 1, ny = 1;
|
|
|
|
// FIXME: We actually need ny to be 1 regardless of the decomposition,
|
|
// since the task decomposition is one scanline high.
|
|
|
|
if (programCount == 8) {
|
|
// Do two pixels at once in the x direction
|
|
nx = 2;
|
|
if (programIndex >= 4)
|
|
// And shift the offsets for the second pixel's worth of work
|
|
++du;
|
|
}
|
|
else if (programCount == 16) {
|
|
nx = 4;
|
|
ny = 1;
|
|
if (programIndex >= 4 && programIndex < 8)
|
|
++du;
|
|
if (programIndex >= 8 && programIndex < 12)
|
|
du += 2;
|
|
if (programIndex >= 12)
|
|
du += 3;
|
|
}
|
|
|
|
// Now loop over all of the pixels, stepping in x and y as calculated
|
|
// above. (Assumes that ny divides y and nx divides x...)
|
|
for (uniform int y = y0; y < y1; y += ny) {
|
|
for (uniform int x = 0; x < w; x += nx) {
|
|
// Figure out x,y pixel in NDC
|
|
float px = (x + du - (w / 2.0f)) / (w / 2.0f);
|
|
float py = -(y + dv - (h / 2.0f)) / (h / 2.0f);
|
|
float ret = 0.f;
|
|
Ray ray;
|
|
Isect isect;
|
|
|
|
ray.org = 0.f;
|
|
|
|
// Poor man's perspective projection
|
|
ray.dir.x = px;
|
|
ray.dir.y = py;
|
|
ray.dir.z = -1.0;
|
|
vnormalize(ray.dir);
|
|
|
|
isect.t = 1.0e+17;
|
|
isect.hit = 0;
|
|
|
|
for (uniform int snum = 0; snum < 3; ++snum)
|
|
ray_sphere_intersect(isect, ray, spheres[snum]);
|
|
ray_plane_intersect(isect, ray, plane);
|
|
|
|
// Note use of 'coherent' if statement; the set of rays we
|
|
// trace will often all hit or all miss the scene
|
|
cif (isect.hit)
|
|
ret = ambient_occlusion(isect, plane, spheres, rngstate);
|
|
|
|
// This is a little grungy; we have results for
|
|
// programCount-worth of values. Because we're doing 2x2
|
|
// subsamples, we need to peel them off in groups of four,
|
|
// average the four values for each pixel, and update the
|
|
// output image.
|
|
//
|
|
// Store the varying value to a uniform array of the same size.
|
|
// See the discussion about communication among program
|
|
// instances in the ispc user's manual for more discussion on
|
|
// this idiom.
|
|
uniform float retArray[programCount];
|
|
retArray[programIndex] = ret;
|
|
|
|
// offset to the first pixel in the image
|
|
uniform int offset = 3 * (y * w + x);
|
|
for (uniform int p = 0; p < programCount; p += 4, offset += 3) {
|
|
// Get the four sample values for this pixel
|
|
uniform float sumret = retArray[p] + retArray[p+1] + retArray[p+2] +
|
|
retArray[p+3];
|
|
|
|
// Normalize by number of samples taken
|
|
sumret /= nsubsamples * nsubsamples;
|
|
|
|
// Store result in the image
|
|
image[offset+0] = sumret;
|
|
image[offset+1] = sumret;
|
|
image[offset+2] = sumret;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
export void ao_ispc(uniform int w, uniform int h, uniform int nsubsamples,
|
|
uniform float image[]) {
|
|
ao_scanlines(0, h, w, h, nsubsamples, image);
|
|
}
|
|
|
|
|
|
static void task ao_task(uniform int width, uniform int height,
|
|
uniform int nsubsamples, uniform float image[]) {
|
|
ao_scanlines(taskIndex, taskIndex+1, width, height, nsubsamples, image);
|
|
}
|
|
|
|
|
|
export void ao_ispc_tasks(uniform int w, uniform int h, uniform int nsubsamples,
|
|
uniform float image[]) {
|
|
launch[h] < ao_task(w, h, nsubsamples, image) >;
|
|
}
|